Party-line bell.



, PATENTED DEC. 15, 1903. L. MOORE. PARTY LI-NE BELL. APPLICATION FILED APR; 16, 1903.

2 SHEETS-811E111 1.

H0 MODEL.

a: minus Penms co moraunom wAsumi'rmn. n cy PATENTED DEC. 15, 1903.

I L. MOORE.

PARTY FINE BELL. 'AIPLIOATION FILED A23. 1a. 1903.

2 SHEETS-8 HEB-'1 2.

N0 MODEL.

Patented December 15, 1903.

PATENT OFFICE.

LELAND MOORE, OF BROOKLYN, NEW YORK.

PARTY-LINE BELL.

SPECIFICATION formingpart of Letters Patent No. 746,979, dated December 15, 1903.

Application filed April 16, 1903. Serial No. 152,847. (No model.)

To all whom it may concern:

Be it known that I, LELAND Moons, a citi- 4 zen of the United States, and a resident of the borough of Brooklyn, in the county of Kings, in the city and State of New York, have made certain new and useful Improvements in Party-Line Bells, of which the following is a specification.

This invention relates to polarized electromagnetic bells which respond. to short impulses of current and yield a vibrating sound or tone. 1

The object is to provide a bell for use on party-lines-that is, lines having two or more pairs in position in close proximity whereby a keeper is formed which maintains the permanentmagnetism unimpaired. I also; separate the other pair of magnet-poles and bridge the space between the permanent-magnet terminals and the vibrating electromagnet-core by a cylinder or cylinders of soft iron having equal or greater mass or crosssection than the polar terminals. I am thus able to provide a magnet of economical construction and increased strength which is readily adjustable by simply turning the cylinders. These cylinders are both constructed of magnetic metal when it is desired to render the bell responsive to both positive and negative impulses, and one is of magnetic -metal and the other of non-magnetic metal when it is desired to render the bell responsive to impulses of one polarity only, and the -magnetic metal cylinder may be located on one side in one bell and on the opposite side in a second bell, the companion cylinder of non-magnetic metal being placed upon the .opposite side in each case, together with a retracting-spring which operates to prevent chattering.

There is an important distinction, measured by a wide extent of utility, in employing what I term cylinders of metal for one pair of pole-terminals, which cylinders are of squalor greater mass orcross-section than the pole of the magnet itself, as compared with the ordinary screw contacts or stops familiar in polarized relays and similar apparatus. The distinction. lies in the greater strength of polar magnetism, in the facility for bringing the full-sized polar terminals close to the vibrating core, and in the ease of adjustment.

I wind the helical convolutions of the electromagnet from a central point on the core toward the poles and return, so that the last layer-the outside layercontains the two ends of the winding.

the wire can be brought out to the fixed posts or terminals in case the vibratory movement results in breaking off the wire close to the winding.

Theaccompanying drawings illustrate my invention.

Figure 1 is a plan view of the bell. Fig. 2 is a side view. Fig. 3 is a cross-section on the line AB, Fig. 1. Fig. 4 is a detail view of the cylinder forming. the pole-terminal. Figs. 5 and 6 show the method of winding the wire on the electromagnet. Fig. 7 shows two bells in a party-line circuit with means for connecting intermittent impulses of either polarity therewith.

There is a base-board b, to which is firmly fixed in an upright position the horseshoe permanent magnet 13. A single-spool electromagnet e, having a soft-iron core 0, is pivoted at or near a point midway its poles on the points 9 and 10 by means of the vertical rod 11, to which the coil is fixed. Permanent magnet p is provided with two iron straps .9, arranged upon opposite sides of the coil e, parallel with the core a. One pair of pole-terminals 0 and q are turned at right angles toward the core a and with the core 0 act asa keeper to maintain the strength of the magnet 19. The opposite ends of the straps or and n are perforated and screwthreaded to receive cylinders of metal a, having a mass or cross-section equal to or greater than the mass or cross-section of the strap. The adjacent end of the core 0 is encircled by a band of copper d. By making these cylinders a. of large mass I am able to bring the permanent-magnet poles and the full strength of the magnetism close to the The benefit of this is found in the facility with which the end of poles.

core 0. I am also enabled to make the bells respond to impulses of one polarity only or to both polarities. In order to make the bells respond to both polarities of impulses or an alternating current, I construct both cylinders a of magnetic metal, such as iron. The magnetic cylinders have a contact-point a; of non-magnetic material, Fig. 4. To cause the bell to respond to one polarity only, I place amagnetic cylinder on one side and a non-magnetic cylinder on the opposite side. In this case the hammer will be attracted to or strike on the side bearing the magnetic cylinder and will rest on the opposite side while currents of the opposite polarity are on the line. To guard against chattering, I provide the spring 41 with the adjustingspindle 42. The spring is connected to rod 40, which is firmly fixed to the pivot-rod 11. The adj usting-spindle 42 is located in a tapering hole in the permanent magnet and is split or cut to give it resilience. bell is made to respond to alternating currents and two magnetic metal cylinders are used, the spring 41 is thrown out of action.

it is a hammer or striker fixed to the core 0, and there are gongs or sounding devices g fixed to the base-board b.

In Figs. 5 and 6 Ishow the special winding of the magnet-coil e. The insulated Wire w is wound from the center outward toward the The nextlayer is reversed and several layers are thus superposed. It results from this winding that the terminals 20 and 21 are both terminals of outside layers,and when the vibrations of the magnet operate to break the wire or when the wire is broken from any cause the coil may be uncovered and the wire unwound sufficiently to lead out new terminals 20 and 21. In the absence of this device constituting my improved winding it would be necessary to rewind the coil to obtain at least one of the ends 20 or 21.

In Fig. 7 I have shown a telephone-line i with two telephone-stations, at each of which there is a hand-telephone tand a battery-transmitter u with its local battery 22. There is a gravity-switch 26, with telephone branch 25, and the bell branch 24, containing condenser 23. At a third station there are located two generators of electricity 29 and 30, having opposite terminals connected to ground-wire 31. There is a switch 0" and switch-contacts 27 and 28 connected, respectively, to the positive terminal of one generator and the negative terminal of the other generator. A trailing contact j is permanently connected to line i and rests upon a constantly-rotating wheel or disk It. The periphery of rotatable disk It is divided into conducting and non-conducting sections, so

When the other station only. Either bell may be made to respond to positive impulses alone by the proper location of the magnetic and non-magnetic cylinders 01., and either bell may be made to respond to both positive and negative that is, to alternating currents-by employing two magnetic cylinders a. The trailing contact j, disk It, and switch r are assumed to be at a central telephone-station. These elements form only a fragmentary part of the necessary communicating apparatus, but are sufiicient for an illustration of the operation of my improved bell.

What I claim, and desire to secure by Letters Patent, is-

1. In a polarized bell or sounding device the combination of an electromagnet pivoted at or near the center of its major axis, a permanent magnet fixed in position and having two pairs of magnetic poles composed of strapiron, each strap extending parallel with and upon opposite sides of said magnet-coil, one pair of permanent magnet pole-terminals being formed by bending the strap ends at right angles into close proximity, the other pair of pole-terminals consisting of screw-threaded cylinders of metal of equal or greater crosssection as compared with said strap, each cylinder passing through a strap and bridging the space between the strap and the core of said coil-magnet, a hammer or striking device fixed to the coil and a suitable gong or sounding device.

2. The combination in an electromagnetic vibrating bell of a single coil and soft-iron core pivoted at or near a point equidistant the poles, a permanent magnet fixed in position having two pairs of magnetic poles composed of strap-iron, each strap extending parallel with and upon opposite sides of said magnet-coil, one pair of permanent magnetic pole-terminals being formed by bending the strap ends at right angles into close proximity; a retracting-spring for the pivoted magnet normally holding the core to one side, screw-threaded cylinders of metal, one magnetic and one non-magnetic forming terminalsfor the second pair of poles, the nonmagnetic cylinder being located on the same side with the spring, the magnetic cylinder LELAND MOORE.

Witnesses:

THEODORE L. CUYLER, J r., A. M. DONLEVY. 

